Masonry Compressive Strength f'm, Unit-Strength Method (TMS 602 Table 2)

From the net-area unit strength and the mortar type by the TMS 602-16 Table 2 unit-strength method, no prism test. f'm is not the unit strength: a 2,000 psi (net) concrete unit gives f'm 2,000 psi in Type M or S mortar but only 1,750 in Type N, a 12.5% cut from the mortar alone; a 3,250 psi unit in Type M/S gives 2,500 (77% of the block). Linear interpolation between Table 2 rows; 2,000 psi is the ASTM C90 net-area minimum and the table caps f'm (a higher value needs a prism test). Feeds the CMU wall axial, flexure, and shear checks, and the masonry anchor bolt. A specification aid, not a substitute for TMS 602 and the engineer of record.

f'm = TMS 602-16 Table 2 (concrete masonry, unit-strength method), interpolated on the net-area unit strength for the mortar type: Type M/S 2000->2000, 2600->2250, 3250->2500, 3900->2750, 4500->3000; Type N 2000->1750, 2650->2000, 3400->2250, 4350->2500 psi.

TMS 602-16 (ACI 530.1 / ASCE 6) Specification for Masonry Structures, Article 1.4 B unit-strength method, Table 2 for concrete masonry, by name.

The unit-strength method and Table 2 relationship (2,000 psi unit -> f'm 2,000 in Type M/S, 1,750 in Type N) are reproduced free in CMHA/NCMA TEK notes and state-masonry-association technical bulletins; the interpolation arithmetic is public.

Estimate. AHJ and licensed professional govern.

Field names used by the API: unit_type, unit_strength_psi, mortar_type, f_m_psi

• Concrete masonry only the concrete-masonry Table 2 branch; the clay-masonry branch is a future additionTMS 602-16 Table 2
• Mortar type matters for the same unit, Type N mortar yields a lower f'm than Type M or S (a 2,000 psi unit gives 2,000 vs 1,750 psi)TMS 602-16 Table 2
• Method limits 2,000 psi is the ASTM C90 net-area minimum; the table caps design f'm, and a higher f'm requires a prism test / record of testsTMS 602-16 / ASTM C90